(a) Field of the Invention
The present invention relates to a gas-singeing apparatus which permits blowing flames against both surfaces of an open knitted fabric to burn off the useless naps or fluffs so as to improve the quality of the knitted fabric.
Generally, the open knitted fabrics are highly stretchable and tend to have curls on their selvages. The higher a tension applied to the knitted fabric, the more the fabric stretches and hence its width decreases, not only losing the normalcy of the stitches but also causing the selvages to curl more easily.
(B) Description of the Prior Art
Conventionally, an open knitted fabric introduced into entrance guide rolls is expanded by an expander, such as a tricot guider, and then passed in an S-curve around two suction rolls in a gas-singeing section, where the naps or fluffs on both surfaces of the knitted fabric are burnt off.
The above mentioned suction rollers serve to move the knitted fabric while sucking and holding the same. If the knitted fabric has wrinkles or curls on its selvages left while passing around the suction rollers, satisfactory gas-singeing cannot be attained, causing unevenness of treatment to be introduced into the subsequent processes including dyeing.
The conventional apparatus has a disadvantage that new curls tend to be produced again on the selvages of the open knitted fabric in a course from the expander to the suction rollers.
Further, the conventional suction roller is in the form of a cylinder having a number of perforated small holes in the peripheral surface and one end thereof is connected to a suction producing device. Therefore, the suction force acting on the small holes of the roller tends to be nonuniform longitudinally of the roller. As a result, the holding of the knit fabric by suction becomes nonuniform widthwise of the fabric, so that at the end where the suction force is weak, wrinkles and curls are liable to be produced, forming a cause of unevenness of the singeing effect.
Further, conventionally, the knitted fabric is sucked directly onto the peripheral surface of the suction roller, so that flames pass through the fabric only at places where the small holes exist while at places between small holes the flames cannot pass through the fabric, thus producing unevenness of the singeing effect.
Further, the conventional gas burner is designed so that only the angle of the flame jet can be adjusted.
Only the adjustment of the angle of the flame jet is not effective enough for setting the optimum singeing conditions and said design is inconvenient when it is necessary to adjust the distance between the gas burner and the suction roller in accordance with flames in an optimum condition.